Providing in package power supplies for integrated circuits

ABSTRACT

A device with an in package power supply may be utilized to supply power to other components. As a result, the overall system size may be reduced and economies may be achieved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.10/113,502, filed on Apr. 1, 2002.

BACKGROUND

This invention relates generally to techniques for providing a source ofpower to an integrated circuit.

All integrated circuits require a power supply. Commonly, the powersupply is its own integrated circuit, which electrically couples to thepowered device. For example, the powered device and the power supply mayboth be attached to a printed circuit board and connected to one anotherthrough electrical traces on the circuit board. As a result of the needfor a separate integrated circuit to supply power, the overall size andcost of the resulting components may be increased.

Thus, it would be desirable to provide a power supply that reduces thesize and/or cost of the end electrical product.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depiction of one embodiment of the presentinvention;

FIG. 2 is an enlarged, cross-sectional view of another embodiment of thepresent invention;

FIG. 3 is a schematic depiction of still another embodiment of thepresent invention;

FIG. 4 is an enlarged, cross-sectional view of yet another embodiment ofthe present invention;

FIG. 5 is an enlarged, cross-sectional view of still another embodimentof the present invention;

FIG. 6 is a bottom plan view of the embodiment shown in FIG. 5; and

FIG. 7 is an enlarged, cross-sectional view of another embodiment of thepresent invention.

DETAILED DESCRIPTION

Referring to FIG. 1, a system board 10 may mount a battery 12 coupled toan integrated circuit device 14 that may be a flash memory, for example.The device 14 may include a power supply in package (PSIP) 16 in oneembodiment of the present invention. In effect, the power supply isintegrated right into the same integrated circuit package that forms thedevice 14. This may result in considerable cost and/or size reduction ofthe resulting board 10.

However, other integrated circuits on the same board, such as integratedcircuit 20, may then need a power supply. The integrated circuit 20could be supplied by a separate integrated circuit power supply.However, the use of separate power supplies partially defeats thepurpose of integrating the power supply into the device 14.

Many types of devices on a system board 10 of processor-based systemsmay not be activated at the same time. For example, different types ofmemory sharing the same data bus may never be activated at the sametime. As one example, a flash memory device is generally not activatedat the same time a static random access memory (SRAM) is accessed. Thus,whenever the device 14 is not being utilized, its PSIP 16 may beelectrically coupled by a link 18 to an integrated circuit 20. Forexample, the link 18 may be a metal line on a printed circuit board inan embodiment where the board 10 is a printed circuit board. Thus, whenthe device 14 is in operation, it receives power from the PSIP 16. Whenthe device 14 is not in operation, the power from the PSIP 16 may besupplied to another, active integrated circuit, such as the integratedcircuit 20.

As a result, the size of the system board 10 may be decreased because itis not necessary to provide additional power supplies for eachcomponent. Therefore, the cost of the system board 10 may also bereduced. The cost of integrated circuit 20 may also be reduced since itmay not need its own PSIP circuitry.

Referring to FIG. 2, a packaged integrated circuit 22 may include a pairof spaced dice 24 a and 24 b, one positioned above the other, in oneembodiment of the present invention. The die 24 a may be coupled to aPSIP 16 via a link 26. The die 24 b may be coupled to the die 24 a toreceive power from the PSIP 16. As long as the dice 24 a and 24 b arenot operated at the same time, as described previously, a single inpackage power supply 16 may be utilized to supply both dice 24 a and 24b, for example, using an electrical coupling 28 to supply power to thedie 24 b through the die 24 a.

In one embodiment, the packaged integrated circuit 22 may include aplurality of solder balls 30 to make external contacts. However, otherpackage architectures may be utilized as well.

Referring to FIG. 3, an electronic system 32 may include a plurality ofintegrated circuits including the integrated circuit (IC) 38. If theregulator 36 and integrated circuit 38 combination uses a lower supplyvoltage than other components of the system 32, it is difficult to testall the components in the system 32 using a single power supply.

However, a single power supply may be utilized and a voltage droppingcircuit element 34 may be connected to that power supply. Then theintegrated circuit 38 and regulator 36 combination may receive a lowervoltage even though the system 32 only generates a single test voltage.In particular, the input supply voltage supplied to the system 32 may bedropped by the voltage dropping circuit element 34 and then supplied toa voltage regulator 36. The lower voltage regulator 36 in turn providesthe regulated voltage to the integrated circuit 38.

The voltage dropping circuit element 34 may simply be one or moretransistors or diodes in some embodiments. Each of the transistors ordiodes may drop the supply voltage by 0.7 volts, or any other thresholdvoltage, or multiples thereof.

Referring to FIG. 4, an integrated circuit package 41 may include asubstrate 50 in one embodiment. An encapsulant 52 may encapsulate anintegrated circuit die 40. The die 40 may include its own discretecomponent 44 for purposes of supplying a supply voltage from within thepackage 41. For example, the discrete component 44 may be an integratedinductor or capacitor.

The discrete component 44 may be secured by a suitable adhesive 46, inone embodiment, to the integrated circuit die 40. The discrete component44 may be electrically coupled to bond pads 42 a and 42 b on theintegrated circuit die 40 through wire bonds 48 a and 48 b. The use ofwire bonds facilitates the attachment of the discrete component 44electrically to the integrated circuit die 40. Thus, an integratedcircuit package 41 may include its own power supply, with discretecomponents, all packaged together.

A wire bond from the discrete component 44 may also be attached to thesubstrate in another embodiment. The discrete component 44 may also beadhesively attached to the substrate 50 and may be wire bonded to thesubstrate 50 in another embodiment.

Turning next to FIGS. 5 and 6, an integrated circuit package 60 mayinclude a die 62 within an encapsulant 70 in one embodiment of thepresent invention. A discrete component 64 may be secured to theunderside of the die 62. Again, the discrete component 64 may be anintegrated capacitor or inductor, or other component to enable an inpackage power supply. A substrate 66 is formed on the lower surface ofthe encapsulant 70. However, the substrate 66 has an open centralportion 71 that allows for the passage of the discrete component 64.

As a result, the package 60 may have a lower profile because there is nointerference between the substrate 66 and the discrete component 64,particularly because of the open central portion 71 of the substrate 66.The substrate 66 may provide electrical connections to the exteriorenvironment, for example, through solder balls 68, in one embodiment.The substrate 66 may also provide wire bond connections 69 to thecomponent 64 that may thereafter be encapsulated with encapsulant 73.

Thus, as shown in FIG. 6, the discrete component 64, incorporated toprovide an in package power supply, may protrude through the opencentral portion 71 in the substrate 66 and may be suspended, withoutinterfering with any underlying structures, through the vertical gapcreated by the combination of the substrate 66 and the solder balls 68.

Referring to FIG. 7, in an alternate embodiment, the package 60 a mayinclude an encapsulant 70 a. The die 62 may have a pair of contact pads72 in one embodiment. The contact pads 74 electrically contact metalliccoatings 72 on the sides of the discrete component 64. Thus, thecomponent 64 may simply be plugged into the receptacle defined by thecontact pads 74.

While the present invention has been described with respect to a limitednumber of embodiments, those skilled in the art will appreciate numerousmodifications and variations therefrom. It is intended that the appendedclaims cover all such modifications and variations as fall within thetrue spirit and scope of this present invention.

1. A method comprising: supplying power to an integrated circuit using a power supply in a package with the integrated circuit; and selectively supplying power to a component from the power supply external to the package when the integrated circuit is not in operation, using a lower supply voltage than said integrated circuit.
 2. The method of claim 1 wherein supplying power to an integrated circuit comprises supplying power to a memory.
 3. The method of claim 1 wherein supplying power to a component comprises supplying power to a memory.
 4. The method of claim 1 wherein supplying power to a component comprises supplying power to a component on a board on which the integrated circuit and the power supply are mounted.
 5. The method of claim 1 wherein the package is a first package and wherein supplying power to a component comprises supplying power to an integrated circuit in a second package separate from the first package. 